Instruction manual

SM425 INSTRUCTION MANUAL 11.0 INSPECTION and MAINTENANCE
11.1.7 Process Shutdown and Startup
<Process Shutdown>
Follow these precautions to prevent sensor damage during process shutdown.
Processes such as boiler and industrial furnace operations can entrain significant amounts of particulate
and moisture in the gas stream that can be deposited on the zirconia cell during process shutdown and
startup. Since the sensor is heated to 750°C, these deposits can become firmly fixed and degrade sensor
performance. If there is a large amount of condensation, the sensor can be damaged and become
unusable.
To prevent this from occurring, take the following actions when shutting down a process.
(1) Either keep the converter powered up and reference air flowing to the sensor or remove the detector.
(2) If this is not possible, supply air to the calibration gas pipe at 600ml/min.
<Process Startup>
During process startup, supply air to the calibration gas pipe at 600 ml/min for 5-10 minutes before
supplying the power to converter.
11.2 Inspection and Maintenance of the Converter
11.2.1 Cleaning
The touch panel should be kept clean by wiping off with a soft dry cloth.
Use a soft dry cloth to clean any part of the converter during inspection and maintenance.
11.2.2 Adjusting LCD screen contrast
An LCD screen is built in the SM425 converter. The contrast of this LCD screen is affected by its ambient
temperature. The conveter is shipped with the contrast adjusted at a room temperature of 20-30°C. If the
LCD display is hard to see under operating conditions, adjust the LCD screen contrast with the variable
resistor shown in Figure 11-5.
182 42500001 REV A